P0420 Remedy (sparkplug non fouler)

Jimsun · Feb 15, 2014

Hey guys,
My smog/emission test is coming up this summer and i have yet to figure out a remedy for my p0420 code.

I have read that a cheap fix would be to use the spark plug non fouler BUT the 18mm won't fit on my O2 sensor. It seems to be too short for it to fit

Has anyone found a fix for this?

I was thinking of drilling straight through it to make it fit.
Any thoughts guys?

http://imageshack.com/a/img837/2563/rd8c.jpg

001Stunna · Feb 15, 2014

Yes, you use a 1/2" drill bit & drill through it. You might have to use 2 spark plug non foulers if your cat converter is really shot/or if you use a test pipe.

Jimsun · Feb 15, 2014

001Stunna said:
Yes, you use a 1/2" drill bit & drill through it. You might have to use 2 spark plug non foulers if your cat converter is really shot/or if you use a test pipe.

Whats a test pipe?

The thing with my o2sensor is that there isn't a hole in the middle of the surface tip. All the holes are at the sides. Will that be ok?

The downstream o2sensor's job is just to monitor less of the co2 that's going back out right?

001Stunna · Feb 15, 2014

Jimsun said:
Whats a test pipe?

The thing with my o2sensor is that there isn't a hole in the middle of the surface tip. All the holes are at the sides. Will that be ok?

The downstream o2sensor's job is just to monitor less of the co2 that's going back out right?

A test pipe is hollow exhaust tubing shaped like a cat.converter. It is "ideally" illegal to be used in the street but that doesn't mean everyone abides by the law.

The rear o2 sensors job is to monitor the converter, compare its signal with the front o2 and deem if your converter is operating in the required efficiency or not.

I'm not sure what you mean by the holes are to the sides. What you got to do is...
-remove o2 sensor of the converter(might be a a bit hard)
-use a 1/2" drill bit to open up the spark plug non fouler and screw it on the converter. use a bit of grease on the threads to help it go in.
-do the same and thread the 2nd non fouler onto the first one after you've extended it.
-again with a bit of grease install the o2 sensor on the second non fouler.
-plug in the connector and hook the wire on the clip provided so its not just dangling and call it a day.

*depending on where the hole is on your converter you might not be able to use 2 non foulers if its facing up as it might cause your o2 sensor to hit the underside of the car if you ever hit your exhaust on something.

Jimsun · Feb 15, 2014

001Stunna said:
A test pipe is hollow exhaust tubing shaped like a cat.converter. It is "ideally" illegal to be used in the street but that doesn't mean everyone abides by the law.

The rear o2 sensors job is to monitor the converter, compare its signal with the front o2 and deem if your converter is operating in the required efficiency or not.

I'm not sure what you mean by the holes are to the sides. What you got to do is...
-remove o2 sensor of the converter(might be a a bit hard)
-use a 1/2" drill bit to open up the spark plug non fouler and screw it on the converter. use a bit of grease on the threads to help it go in.
-do the same and thread the 2nd non fouler onto the first one after you've extended it.
-again with a bit of grease install the o2 sensor on the second non fouler.
-plug in the connector and hook the wire on the clip provided so its not just dangling and call it a day.

*depending on where the hole is on your converter you might not be able to use 2 non foulers if its facing up as it might cause your o2 sensor to hit the underside of the car if you ever hit your exhaust on something.

Heres what i meant.

The sensor for the ulev doesn't have the hole on the bottom surface that faces the hole of the fouler.

Here are some pics.

Should i just drill through the first non fouler and connect it to the cat or attach the second non fouler?

As you can see from the pic, i did not drill all the way through before i didnt know whether to do so or not.

Jimsun · Feb 15, 2014

Heres an update to the other one Since i can have 2 without worrying about clearance

001Stunna · Feb 15, 2014

I drilled all the way through on both of mine. Had them like that for quite awhile...no issues and I can pass the new etest with no issues.

For me it was easier to install one on the converter, tighten it, install the 2nd and tighten it and then install the sensor.

Jimsun · Feb 15, 2014

001Stunna said:
I drilled all the way through on both of mine. Had them like that for quite awhile...no issues and I can pass the new etest with no issues.

For me it was easier to install one on the converter, tighten it, install the 2nd and tighten it and then install the sensor.

Thanks

I currently installed it with only 1 drilled through. I will fully drill it after. Thanks

justin_l_ · Feb 16, 2014

If you have a welder you can weld a couple o2 sensor bungs on top of each other. Mor permanent solution without drilling. Just use a bolt or tap to keep the threads aligned while welding.

Jimsun · Feb 23, 2014

I havent drilled the second hole but after clearing the code that same day and driving it for 2 weeks. It seemed to be holding up. Did a read via obd2 and it says its ready

.

P0420 Remedy (sparkplug non fouler)

Jimsun

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